Battery charging can generate a significant fire risk, from overheating, short circuit, or from the lead-acid battery charging process, which produces hydrogen gas. Hydrogen is highly flammable. It can be ignited to cause a significant fire, even in small concentrations. Sparking when attaching the leads to a battery can be enough to ignite hydrogen. We’ve listed some top tips below, this list isn’t exhaustive, but should help you identify some of the key concerns, helping you complete your fire risk assessment
- Fires can result from electrical faults within the charging unit, the attached cables, the truck or the battery on charge. Undertake regular checks of the cables and chargers, to ensure that they are maintained in good condition (add this to your daily FLT safety checks). All electrical connecting leads should be as short as possible to minimise potential for physical damage. Care should be taken to prevent mechanical damage to cable when not in use. If possible the battery should be removed from the truck whilst being recharged. If the battery cannot be removed, the battery compartment should be kept open during recharging.
- Battery charging should be carried out in a separate building of non-combustible construction specifically reserved for this purpose. Ideally the charging area should be separated from other areas by a fire rated enclosure providing at least 60 minutes fire resistance, including any doors. Keep the area less than 50m.sq, unless the area is sprinkler protected. Ideally access into these areas should be from external doors, if at all possible.
- Where it is not possible to provide a fire-separated area, battery charging should be confined to a designated area within the building. Charging units should be installed and securely mounted off the floor on a non-combustible wall. Suitable signage should be provided
- Areas used for battery charging should be kept clear of any combustible materials and away from flammable liquids. A minimum clearance of at least two metres is recommended. Fixed metal barriers should be provided to control access to the area, prevent storage and reduce the risk of accidental damage to the charging equipment. Alternatively painted lines on the floor may help designate the area and help keep the area clear of storage.
- During battery charging, hydrogen gas is generated and can create a highly explosive atmosphere. The charging area should be well ventilated, preferably by natural means. Mechanical ventilation may be required, however this should not introduce any additional hazards and should be appropriately rated for the environment. The risk of explosion can be reduced by using maintenance free batteries.
- Follow the manufacturers safety guidance for the time/rate of charging. Charging should be undertaken whilst staff are on site, otherwise you risk a fire occurring whilst the premises are unoccupied, which could result in a delay in fire-fighting. Where charging is carried out in an unmanned area overnight, automatic fire detection linked into the building fire alarm system and off-site signalling to an Alarm Receiving Centre, should be installed.